Jason P. Briner is looking for an answer buried deep in mud
dozens of feet below the surface of lakes in the frigid Canadian
Arctic.

His group is gathering the first quantitative temperature data
over the last millennium from areas in extreme northeastern
sections of the Canadian Arctic, such as Baffin Island.

Every spring, Briner, Ph.D., assistant professor of geology in
the College of Arts and Sciences at the University at Buffalo,
travels to the region to sample Arctic lake sediments and glaciers
and analyzes them to reconstruct past climates.

"As paleoclimatologists, we want to study Earth under conditions
similar to those we have today, what we call 'climate analogues,'
which might tell us what to expect in the future," he said.

The Arctic as a region is an excellent harbinger of future
change, Briner said, because the signals or clues that signify
climate change are so much stronger in the Arctic than elsewhere on
the planet.

"Yet, even when we take that phenomenon into account," he noted,
"the signals we're finding on Baffin Island are huge," he said.
"The temperature records, that is, the 'signal' of warmth that
we're reconstructing for this part of the Canadian Arctic over the
past 10,000 years seems to be higher than the global average for
that period and even higher than the Arctic average."

For example, during the 'Holocene thermal maximum,' the warmest
period of the past 10,000 years, the Arctic average temperature was
two to three degrees warmer than it is today, while the global
average was only a degree or so warmer.

"But based on lake sediments from Baffin Island, our data show
that this area of the Arctic experienced temperatures five degrees
warmer than today," said Briner.

Briner and his co-authors published these results last May in
Quaternary Research (Vol. 65, pp. 431-442). The co-authors were N.
Michelutti, formerly of the University of Alberta; D.R. Francis of
the University of Massachusetts; G.H. Miller of the University of
Colorado; Yarrow Axford, Briner's post-doctoral research associate
at UB; M.J. Wooller of the University of Alaska, Fairbanks; and
A.P. Wolfe of the University of Alberta.

Because Arctic regions show such strong seasonality, Briner
explained, it's relatively easy to correlate climate changes with
very fine layers in the sediments. In some lakes, each layer
represents one year, with thicker sediment layers generally
signaling warmer summers.

Like other paleoclimatologists, he also is finding that the
warming trend that began in the 20th century is more pronounced in
the Arctic than it is in the rest of the globe.

"The magnitude of warmth over the past 100 years seems pretty
exceptional in the context of the past 1,000 years," he said.

"Whereas maybe an average of all of the instrument data from the
globe shows just a half a degree increase in this century, in the
Arctic, temperatures went up by two to three degrees in the same
period."

The rapidity of the change also is exceptional, he added.

"If we look at the temperature graphs that we've generated for
the past 1,000 years for this region, the temperatures wiggle back
and forth, so there is a little variability in there," he said.
"However, in the past 100 years, both the magnitude and the rate of
temperature increase exceed all the variations of the past 1,000
years."

To do the research, Briner and his graduate students and
post-doctoral associates travel to Baffin Island and other areas in
extreme northeast Canada each May, while it is still winter
there.

They fly to remote Eskimo villages, and then drive snowmobiles,
dragging their gear behind them on sleds, for hours across the
tundra and sea ice. Once they reach a good sampling site, they set
up camp nearby and get to work, drilling through the ice and the
water below until their equipment reaches sediments.

"The beauty of lake sediments is that they're being deposited
continuously right up until yesterday," Briner said, "so by looking
at them, we get clues into past climates, which we can then overlap
with records from weather stations, which only cover the past 50 to
75 years."

They then send their samples -- long tubes full of mud -- back
to UB, where Briner and his team analyze them.

Among the clues in the cores are isotopes, fossils and increases
in organic material from the accumulation of dead organisms and
algae.

"Generally, the more organic matter in sediments, the warmer the
climate," said Briner.

A primary goal of the research is to account for spatial
variability when reconstructing past climate records.

"Everyone knows the climate is extremely variable, spatially,"
said Briner. "For example, earlier this year, Colorado got slammed
with snow and Buffalo didn't get a flake. It's the same when we
reconstruct past climates: maybe the climate cooled by 30 degrees
in Greenland but only 10 degrees in the area that's now
Buffalo."

Reconstructing this spatial variability will help develop a more
precise view of how past changes in climate have affected the
planet, Briner says, providing a guide for how the current global
warming trend may unfold.

"We can use these patterns to test climate models," said Briner.
"Once models can adequately predict past climates and their spatial
patterns, then we have confidence that they work and so can be used
to predict the future."

Briner and members of his team will present some of their data
May 2-5 at the 37th Annual International Arctic Workshop in
Iceland.

The research is funded by the National Science Foundation.

The University at Buffalo is a premier research-intensive
public university, the largest and most comprehensive campus in the
State University of New York.

Social Media / RSS

Get essential information and services—from the latest
news and Bulls headlines, to interactive maps, dining and
transportation information, and a lot more—anytime, anywhere,
right from your mobile device. Go mobile today!